The present invention relates to a surgical stapler for applying staples to suture or close a wound or incision, particularly a surgical skin stapler for implanting skin staples in or through the skin to suture an exterior wound or incision.
Surgical staplers are used for closing or connecting conformed wound edges of tissue by implanting metal staples in the tissue. By actuation of a lever, the staple is pressed by a ram or driver against an anvil surface provided at the tip of the stapler tool and is thereby deformed, so that the parts of the staple protruding from the stapler tip are moved toward each other and penetrate into the tissue.
U.S. Pat. No. 4,179,057 discloses a surgical stapler comprising a staple magazine containing a supply of staples, a spring for advancing the staples in the staple magazine, an anvil surface provided at the stapler tip, and a driver displaceable relative to the anvil surface in a staple channel which deforms a staple supported on the anvil surface. In a stapler of the type disclosed in the aforementioned patent, the staples are advanced along a straight feed path in the staple magazine. The forwardmost staple lies in the path of movement of the driver which extends at an angle which appears to be about 50.degree. with respect to the longitudinal axis of the staple magazine. The stapler is actuated in plier fashion to advance the driver which presses the forwardmost staple protruding from the stapler tip against the anvil surface and deforms it to close the staple side portions. At this point, the staple has been implanted and it is necessary to remove from the staple the anvil surface which is fixed to the stapler tip. However, if the stapler has been improperly positioned, it is possible to pull the closed staple out of the tissue when disengaging the anvil surface from the implanted staple.
U.S. Pat. No. 4,202,480 discloses a surgical stapler which also comprises a staple magazine having a straight staple feed path. The staple channel in the stapler in which the driver is displaceable and the staple magazine meet at almost a right angle. The forwardmost staple is advanced by the driver to the anvil surface on which it is deformed with its side portions protruding forwardly of the stapler tip. The anvil surface is transversely disposed at the forward end of the staple channel. It is also difficult to pull the anvil surface of this stapler out of an implanted staple.
U.S. Pat. No. 3,819,100 discloses a surgical stapler comprising a removable staple cartridge which is inserted into and locked to the stapler. The staple cartridge has a straight staple feed path. Staples are advanced by a driver moved by a stepping mechanism. The forward housing portion of the stapler, into which the staple cartridge is inserted, is rotatable relative to the rear housing portion. The anvil surface is fixed at the front end of the staple cartridge.
Prior art surgical staplers have the disadvantage that they did not afford a good view of the work area because the driver moved transversely to the straight staple magazine. Therefore when the stapler was positioned for use, a considerable portion of the work area was obscured. While it is possible to arrange and feed the staples laying flat one behind the other in order provide a slim tool tip affording a better view of the work area, the cost of manufacturing the parts required to accomplish this is high. Moreover, the number of staples that can be accommodated in a staple magazine if the staples lie flat one behind the other is relatively small.